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that is effectively similar to simply ignoring non-aligned matched ... How so?

Although embedding the called-back code within the regex as a zero-length code assertion looks like its not exiting the regex engine; the effect on performance shows that the need to set-up and tear down a scope and invoke that code has a very significant effect:

$s='a'x1e6; cmpthese -1, { a => q[ $s =~ m[(.)(?{$c=pos();})]g; ], b => q[ $s =~ m[(.)]g; ], };; Rate a b a 3924/s -- -100% b 4206322/s 107088% --

If it was possible to avoid running 3 orders of magnitude slower, the benefits would be enormous for my application.


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In reply to Re^6: A regex that only matches at offset that are multiples of a given N? (Update:almost perfect!) by BrowserUk
in thread A regex that only matches at offset that are multiples of a given N? by BrowserUk

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